91bluemetalicRS

Hey how many gaskets do you guys use when installing intake manifolds? I found a leak in mine and will be repairing it next weekend. I have heard some people use just 2 gaskets for the heads and rtv for the front and back of the block. I have always used 4 total (2 for the heads and 2 small rubber pieces for the front/back of the block). Am I confused or do you just need two and lots of rtv. thanks for the help.

llvll4l2c91350

I did an intake manifold on my current car and my previous 88 Formula using only RTV on the front and back. They both started leaking a few days later. When I had the heads replaced the mechanic used RTV on top of rubber gasket for the front and back. Hasn't leaked in over a year.

91bluemetalicRS

see that is exactly what I was thinking. I have always used the rubber up front and in back. Hehe. Leaks are bad. I went to get gaskets the other day and two parts stores told me they don't make them anymore. Anyone got a part # or where I can get them? I guess I could always salvage the ones I have on there now, but I am never that lucky....

llvll4l2c91350

When I did the manifold gasket on my current car I bought the Felpro kit which did not come with rubber for the front and back. But I'm sure they're still out there cuz the guy that did the head work was able to find 'em. But yeah whatever you do, don't use RTV alone.

RB83L69

I haven't put a piece of rubber under he intake of any any motor I've built for at least 2 decades, unless the customer specifically requested that I install a leak.

Smear a thin coating of silicone on both the block and the intake; let it sit for a few minutes; then lay about a ¼" bead of it on the block, paying careful attention to position it exactly where the intake will go (a common mistake is to have the bead not line up with the sealing surface of the intake, whcih will of course leak); let that set up for about ½ hour; then lower the intake onto the block carefully, being certain to get it in the right place the first time.

Works every time, no leaks. That's also how the factory has been doing it since at least the late 70s.

Vader

I've used both the "China wall" gaskets with RTV, and a triple bead or RTV alone (three 1/8" beads in a triangle arrangement). Neither one leaks if you're careful. RB has a lot of building experience, so he has a good history of what does and doesn't work.

Whatever method you use, make sure you apply only sensor-safe RTV sealant at the ends and the water passages. And make sure you use a non-hardening bolt sealant, like Permatex "Seals-Pipes with Teflon" or Loctite PST. Clean the bolt threads AND chase the holes in the heads before applying the compound.

And DON'T stack any gaskets, please.

camaro03

i just bought the gasket set today it came with them, from autozone, ive built many motors and have changed alot of intakes, i always use the rubber for the front and back and silicone both sides and make sure theres plenty of silicone in the corners, i would also silicone the gaskets to the heads so if you you take the manifold off the gasket will stay fixed to the block and most likely be reusble